The debate between Everett and Chomsky is an important and interesting one. Their two poles, culture and biology, mark out a linguistic field that serves my purpose. There are aspects of both views that appeal to me. I agree with Chomsky that language is irrevocably grounded in biology. And I agree with Everett that language is best seen as a tool. Language is a tool we use strategically to carry the freight of meaning from ourselves to others.
Over the years I have come up with my own linguistic rules of thumb. Untutored and unlettered, and lacking in the sophistication of even an undergraduate in the field, I nevertheless hope to publish them for the hope of future development, and for that reason I welcome your comments.
1. People mess things up through use
Languages slowly devolve toward grunts and clicks over time. Prepositions, for example, that used to denote fine shades of difference come to say pretty much the same thing. Similarly, verbs for actions that we do a lot, such as "bring" or "go" or "give" or "enter/exit", become linguistically complicated. The rococo nuances available to a language during an Elizabethan high point erode into simpler modes--shorter sentences, more practical applications, in short, toward the Strunk and White.
2. Language--this is my middle-way between Everett and Chomsky--is about feel and sound
To me Chomsky is right to a degree, in that we only have a finite amount of sounds--even if practically that finitude is infinite, but Everett is also right, in that our culture will choose a set from that near-infinite set and create all words from that chosen subset. Languages could, I suppose, then be classified by subset, and dialects by the agreement or disagreement with the governing subset.
In Greek, for example, we discover a set of sounds (and human sounds are made by how the mouth feels, so feeling may enter, too, into how a culture chooses or dismisses a sound) chosen by that culture. And what culture? Oh, the culture that figured out musical scales and poetical meter. Plato has a section of The Republic devoted to poetic meter. Aristotle also lectured on it. People took it seriously. They listened. Therefore, we are invited to listen as well. At its deepest level, a language is a way of playing jazz on the most important instrument in the universe--the human voice. To learn a language is to be invited to step into the set and learn to jam, and we, like musicians, must learn to listen as well as to play. Playing is good. Listening is better. (A corollary to this is that language is a craft, not a sum.)
3. The observable world makes the rules
There are men, women, and things. There is us and those around us. There is the thing we throw and the thing thrown at us. The world presents problems to every culture, to every speaker, that he or she must solve. Some might also say that one's vocabulary determines what you see in the world. It is a romantic idea. IMHO, the jury is still out on that one.
4. Vowel sounds are the silly putty of language. Consonants, not so much
If you were trying to send a message to people 100 years from now, don't hand it to the vowels. You'd better leave it with the consonants. The effects of this choice are hobgoblin and pervasive.
5. There are two strategies
To my mind, there are two basic strategies for encoding meaning into the extended musical riff we call a sentence: word order and inflection. Your language may borrow something from the other team, but it always emphasizes one or the other.
English is a word-order strategy of sequence and proximity. Related phrases go together. Our subjects come before our objects. Greek is an inflected language. Prefixes and suffixes are added or removed from a word to make it perform in different ways.
The gulf between these two cannot be overestimated. They are not only two strategies, they are two ways of hearing. I'm just starting to realize how much this is true.